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From: brecher@well.UUCP (Steve Brecher)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Tail Patching and ROM replacement
Message-ID: <15080@well.UUCP>
Date: 18 Dec 89 04:53:31 GMT
References: <17539@dartvax.Dartmouth.EDU> <41304@srcsip.UUCP>
Reply-To: brecher@well.UUCP (Steve Brecher)
Distribution: na
Organization: Software Supply, Sunnyvale, CA
Lines: 19


In article <41304@srcsip.UUCP> mnkonar@gorby.UUCP (Murat N. Konar)
writes:
> Tail patching is for quiche-eaters who don't want to learn how 
> the stack works and how to fix things in assembly....
> I'm sure there are rare cases when only a tail patch will 
> work (can't think of any though)...

I haven't been able to think of a way to implement Suitcase II
without tail patching.  By the way, what's a stack?

But seriously... there is one technique that sometimes will let
one eat one's quiche and have it, too.  In some cases it is
feasible to JSR to the predecessor trap code, do some
processing, and then JMP to it -- i.e., execute it twice.  The
target of the JMP would invoke the ROM patch, if any.
-- 

brecher@well.UUCP (Steve Brecher)